Application Of Polyoxymethylene Passive Air Sampler To Monitor Hydrophobic Organics In Air Around A Confined Disposal Facility

Volatile losses of hydrophobic organic contaminants from a confined disposal facility (CDF) containing dredged contaminated sediments is of substantial concern to surrounding communities. A partitioning passive sampling approach using polyoxymethylene (POM) was applied to measure long-term average (weeks to months) air concentrations resulting from evaporation at a CDF. Measurements at 10 locations surrounding the CDF using the POM air samplers indicated that the highest concentrations of Sigma PCBs similar to 13 ng/m(3) and Sigma PAHs similar to 65 ng/m(3) were measured during an active dredge material placement period when the average temperature was 23 degrees C. The measurements were dominated by the more volatile, lower molecular weight compounds of each type. Partitioning to the POM during the post dredge material placement period with average temperature of 5 degrees C was corrected for temperature and the measured Sigma PCBs and Sigma PAHs were similar to 3 ng/m(3) and 45 ng/m(3) respectively. The partitioning passive sampling measurements agreed well with the available weekly 24-h high-volume air samples (HVAS) averaged over the POM equilibration time for lower congener number PCBs (15, 18, 20/28 and 31) and naphthalene but were as much as 10 times lower than HVAS for high molecular weight PAHs. The difference was likely the result of the greater association of these PAHs with particulates and sources other than evaporation from the CDF. The POM air sampler achieved the goal of providing a long-term average air concentration without having to collect, analyze and average multiple HVAS samples although the technique is largely limited to the lower molecular weight PAHs and PCBs and different equilibration times for different compounds complicate its use and analysis. (C) 2020 Elsevier Ltd. All rights reserved.